DESCRIPTION (As Adapted from the Investigator's Abstract): Specific aims of the study are to compare persons with AIDS with non-HIV infected persons on: 1) characteristics of circadian rhythms of body temperature, 2) circadian patterns of salivary melatonin and cortisol, 3) sleep efficiency and level of activity, and 4) associations between temperature and hormonal levels. A descriptive, repeated measures design will compare two groups, those with HIV and those without HIV. Portable multichannel systems are used to monitor skin and core temperatures, along with an activity motion sensor to measure sleep/wake time. Sleep diaries will allow subjects to record subjective sleep quality, timing of meals and exercise. Salivary melatonin and cortisol are collected using pre-rolled cotton gauze and measured by radioimmunoassays and ELISAs, respectively. Cosinor analysis will evaluate both individual and group data. Comparing groups will be measured by independent samples t tests. Disturbed sleep patterns are very common in persons with AIDS and have been linked to drug therapies, night sweats, and depression. Cytokine production is high at late stages of the disease and tend to produce variations in body temperature. Core body temperature is one of the most stable indicators of circadian rhythms. With the day/night changes, circadian rhythms can be found even in the midst of illness, fever, external factors, and increased activity. Because of its stability and the every day use of thermometers, body temperature is often the most frequent method of studying circadianicity (Mason, 1988, p. 277). However, during the last several years, many investigators have added evaluations of various hormones in urine and saliva. The advantages of these methods include non-invasive sampling and have demonstrated reliable correlation to serum levels. Melatonin and cortisol play a crucial role in circadian thermoregulatory adjustments of body temperatures (Saarela and Reiter, 1993). Previous research has shown that massive amounts of cytokines circulate in the HIV-infected individual's serum. It is reasonable to expect that this would affect circadian rhythms and disrupt the normal sleep/wake cycle. Therefore, the purpose of this study is to determine variations in the circadian rhythm, temperature, and sleep/wake cycle in persons with AIDS.